70cc bogging down at full throttle?

I just got a 70cc motor, and so far i've put around 20 miles on it, but it seems to bog down when i give it full throttle. It seems to go fine just below full throttle, but i was wondering if there was a way to adjust it or fix it so it either stoped bogging down or performed better without bogging down at full throttle.

Ours did too.
We tried a few different things, with no success.
We are remounting the engine though, so the new bike will be our test ground for removing that fullthrottle bog.
We were still running 20:1 though, so on the new ride we'll put in a new plug and a new mixture and see what we can come up with.
A plug chop will be first in order on the new bike, as going fast will be our goal with the new ride (the AMF was more of just a cool looking tester)

i think trying to push a full throttle so soon won't give you what you're looking for, search thru our "general discussion" and "technical help" areas to find a whole bunch of good info on break-in theory.

my has been doing the same thing when i go full throtle and its broken in and i run it on 32:1
i just ordered a 36 tooth sprocket hope this makes it stop boging heard what sounds like miracles from other who got the 36 tooth sprocket

hay guys, l just spoke with roland from spookytoothcycles the other day about this same problem, and it fixed it. it only took 2 min. in your carberator there is a pin(long and thin) and it has a black ring, if you look close at it there is 3 postions the black ring will slide on to the pin. 1, 2, and 3 little grooves. mine was at the 1st position and changed it to the 2nd position and my boging went away, here is a pic ,but its best to look at yours........good luck
sorry about the crappy pics

As for not going full throttle on a new engine, that is bad advice. You should take every opportunity to exercise the engine's full rpm range to get a proper break in. If you don't put the engine through its paces, you will never develop sufficient cylinder pressure to seal the rings aginst the piston wall. Also, connecting rods stretch at increasing rpms. If you drive slow the rod won't strech and allow surface mating to occur at those locations where the piston goes when it is revving high. What happens is the cylinder ges mated to the cylinder for only a small portion of its intended travel and when you rev higher you actually cause excess wear from the portion of the cylinder that is slightly smaller in diamter than the rest of it-a taper.

I can go on but too many knucklehead with no engineering degree to back up their knowledge base.

you tell him augidog, l thought we were trying to help, but l guess l'll keep my mouth shut and let them figure it out on there own. as far as engineering l have my mcse, so up yours drewd. we are only trying to help others, and not be an A-hole at the same time, jerk-off.......................don't put others down cause you thing your a genius, which you not.............

Yeah, I tried the clip on every slot (there are 4 slots total in the needle on my carb) and realized that the one groove that it came installed on was the best performing. The 2nd from the top groove... but I'm sending out for an upgraded carb from Simpsons this coming Friday. I can't wait to see how much it will improve. ANd i was checking out that Direct Hit spark plug, but I figured it wouldn't fit on my bike due to lack of space, seeing as how the upgraded plug thing is significantly longer than the stock one. I also have a new idea for a chain shifter whatcha-ma-call-it, and since i have my license back, I can work on it more in the shop when i have some time. but anywho..., and when i get that caqrb, I'll let you guys know how she goes. and If anyone gets one of those direct hit spark things, please let us know how it works, if it's worth it and so-on..

Mine would do that, it was a blown intake manifold gasket. I made another one out of a cereal box, put it on and it made a world of difference.

Click to expand...

My 49cc has been bogging, and I thought my gas had gone bad. I read this thread and thought maby this is the problem. I got the engine warmed up and idling, sprayed a little carb cleaner near the intake manifold, and it started racing then died. This is a shure sign of an intake leak. Made a new gasket, and it runs great.
Thanks Tom